ISO/TC 108/SC 4/WG 13 - Evaluation of human exposure to whole-body vibration

This document specifies dynamic dummies used as replacements for participants in vibration tests of vehicle seats in laboratory. This document is applicable to seats installed in earth-moving machinery, agricultural wheeled tractors, and industrial trucks. This document specifies technical requirements, acceptance criteria, and a validation test for dynamic dummies representing the human body in two mass groups: lightweight (52 kg to 55 kg) and heavyweight (98 kg to 115 kg). It only applies to passive and active dynamic dummies used for vibration tests of vehicle seats in the Z-axis (vertical) direction. This document defines, for the two mass groups, the biodynamic response characteristics that the dynamic dummies are required to reproduce to represent those of the participants to be replaced. This document gives guidance on conducting future research to explore the degree of convergence that can be reached when the dynamic performance of seats is measured with participants and with dynamic dummies conforming to this document. NOTE 1 For seat testing, results have shown that the benefit of using a dynamic dummy is highly dependent on the excitation and dynamic characteristics of the seats. Depending on the type of vibration excitation applied, studies have suggested that the use of dynamic dummies can show benefit over an inert mass of equivalent weight only when testing suspension seats with higher natural frequency (>2 Hz). NOTE 2 The use of dynamic dummies has been reported to tend to overestimate the vibration isolation performance of seats compared with that measured with participants. Several factors can be in cause and require further investigation, one of them being the influence of the legs possibly not being adequately considered when using dynamic dummies.